header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #000;
    color: #fff;
    padding: 10px 20px;
}

.logo {
    font-size: 1.5em;
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    padding: 10px;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: #f0ad4e;
}
.modal {
    display: none;
    position: fixed;
    z-index: 1;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.4);
}

.modal-content {
    background-color: #fefefe;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 30%;
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}
.close:hover,
.close:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}
.login-container {
      display: none;
      position: fixed;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      background-color: #fff;
      border: 1px solid #ccc;
      padding: 20px;
      box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
}


.form-group {
    margin-bottom: 10px;
}

label {
    margin-right: 10px;
}

input {
    padding: 5px;
}

button {
    padding: 10px;
    background-color: #000;
    color: #fff;
    border: none;
    cursor: pointer;
}

button:hover {
    background-color: #333;
}
nav ul {
  list-style-type: none;
  display: flex;
}

nav ul li {
  margin-left: 20px;
}

nav ul li a {
  color: #fff;
  text-decoration: none;
}
/* 鼠标移上菜单文字变色 */
nav ul li a:hover {
  color: #f0ad4e;
}
/* 登录模态框样式 */
.modal {
  display: none;
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: #fff;
  border: 1px solid #ccc;
  padding: 20px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
}